FILE – In this Tuesday, Oct. 8, 2013 file photo, Libyan Prime Minister Ali Zidan speaks to the media during a press conference in Rabat, Morocco. Libya’s parliament ousted the prime minister in a Tuesday, March 11, 2014 vote of confidence, a move prompted by a crisis this week when a militia controlling an eastern port defied Tripoli’s authority by trying to sell oil. The chamber named the defense minister as an interim prime minister until a replacement for Ali Zidan is found. The vote of confidence followed the standoff between the central government in Tripoli and powerful militias in the eastern region of the North African nation. (AP Photo/Abdeljalil Bounhar, File)

FILE – In this Tuesday, Oct. 8, 2013 file photo, Libyan Prime Minister Ali Zidan speaks to the media during a press conference in Rabat, Morocco. Libya’s parliament ousted the prime minister in a Tuesday, March 11, 2014 vote of confidence, a move prompted by a crisis this week when a militia controlling an eastern port defied Tripoli’s authority by trying to sell oil. The chamber named the defense minister as an interim prime minister until a replacement for Ali Zidan is found. The vote of confidence followed the standoff between the central government in Tripoli and powerful militias in the eastern region of the North African nation. (AP Photo/Abdeljalil Bounhar, File)

In this Friday, March 7, 2014 photo made available on Tuesday, March 11 by the Warrior Affairs Commission, Libyan Defense Minister Abdullah al-Thinni addresses soldiers of the Libyan National Army training at an Italian military base in the town of Cassino, about 130 kilometers southeast of the capital Rome. (AP Photo/Warrior Affairs Commission, Stuart Price)

In this Friday, March 7, 2014 photo made available on Tuesday, March 11 by the Warrior Affairs Commission, Libyan Defense Minister Abdullah al-Thinni, center, greets soldiers of the Libyan National Army at an Italian military base in the town of Cassino, about 130 kilometers southeast of the capital Rome. (AP Photo/Warrior Affairs Commission, Stuart Price)

In this Friday, March 7, 2014 photo made available on Tuesday, March 11 by the Warrior Affairs Commission, Libyan Defense Minister Abdullah al-Thinni, center left, greets soldiers of the Libyan National Army training at an Italian military base in the town of Cassino, about 130 kilometers southeast of the capital Rome. (AP Photo/Warrior Affairs Commission, Stuart Price)

In this Friday, March 7, 2014 photo made available on Tuesday, March 11 by the Warrior Affairs Commission, Libyan Defense Minister Abdullah al-Thinni, center, tours a training facility with senior officers of the Italian military at a military base where soldiers of the Libyan National Army trains in the town of Cassino, about 130 kilometers southeast of the capital Rome. (AP Photo/Warrior Affairs Commission, Stuart Price)

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TRIPOLI, Libya (AP) â€” The ousted prime minister fled Libya to Europe after parliament voted him out, leaving behind a country that risks being torn apart as the fault line between its eastern and western regions broke open Wednesday to a degree unseen since the 2011 civil war that ousted longtime strongman Moammar Gadhafi.

A western-based militia fighting in the name of parliament has launched an offensive against an autonomy-minded militia in the east that has for months occupied most of Libya’s crucial oil facilities â€” seizing virtual control of the country’s most vital resource and almost sole source of cash. This past week, it succeeded in exporting a tanker of oil from a port it holds in defiance of the central government.

In response to the offensive other militias in the east are rallying to fight back. Eastern leaders have warned that unless Tripoli backs down they will seek outright independence for their region rather than greater autonomy.

Since Gadhafi’s fall, Libya has been torn among multiple, rival, heavily armed militias affiliated to regions, cities and tribes, while the central government has been weak, unable to bring its authority over the country, inheriting Gadhafi-era military and police forces thrown in disarray. Furthermore, militias have lined up on rival sides of a political struggle between Islamist politicians and their opponents.

Now the success by the Islamist-leaning parliament in voting out secular figure Ali Zidan as prime minister on Tuesday has sparked fears among their opponents of a power grab by the Islamists â€” tensions that also could translate into militia clashes. After the vote, Islamist-allied militias demanded rival militias leave the capital, Tripoli. Instead, some anti-Islamist militias beefed up their positions in the city with armored vehicles mounted with heavy machine guns and anti-aircraft guns.

The Islamist parliament chief, Nouri Abu Sahmein, who had mandated the powerful militia from the western city of Misrata to launch its offensive to win back control of the oil facilities, appeared on Wednesday to be trying to pull back from an outright conflict with the east. In a statement, he said parliament had agreed to give the eastern militia, known as the Cyrenaica Defense Force, two weeks to end its occupation of the oil facilities.

Still, the Cyrenaica Defense Force has already repeatedly refused to withdraw from the ports, and there are concerns the tensions are moving out of control.

“We fear falling into a sea of darkness,” former Interior Minister Ashour Shway told The Associated Press, denouncing the decision to launch the offensive against the eastern milita.

Shway warned that the armed build-up on both sides could led inexorably to conflict. “The drums of war are now banging,” he said, speaking from Benghazi, the country’s second largest city and the heart of the eastern region. “We need sane people to take the lead and stop this from happening.”

The eastern half of Libya â€” where most of its oil resources are located â€” has long complained of discrimination by Tripoli, saying Gadhafi’s government starved it of resources during his 42-year rule. In 2012, a group of politicians, activists and some powerful tribes backed by militias declared autonomy for the